I’m confused, in wikipedia, ordinal regression is also referred as ordinal classification. Which makes sense since ordinal variables are in the end just categorical. On the other hand, ordinal regression is often referred in machine learning as a ranking problem, as we know it from Information Retrieval.
However, if you think about it, ordinal regression is actually not "ranking" (since many values can have the same "ranking") but more a rating, which again is a classical multiclass classification problem?